Leading shares edged higher on Friday at the end of a volatile week, with the FTSE 100 dominated by the Scottish referendum.

The index added 7.34 points to 6806.96, but was down almost 50 points since Monday and fell as low as 6764 during the week, following the various fortunes of the campaign for independence.

Worries about the effect of EU sanctions on Russia, possible US air strikes on Syria and speculation about a possible rise in US interest rates ahead of next week's Federal Reserve meeting all added to the uncertainty.

Associated British Foods, owner of British Sugar and Primark, was the day's biggest faller, down 56p to £26.21. Following Monday's results, where a positive Primark performance made up for a difficult sugar market, Berenberg analysts cut their target price from £30.60 to £28.50. They said:

We had expected EU sugar contract prices to fall from €640 per tonne in the current sugar marketing year (October- September) to €525 for the upcoming year. However, current spot prices and industry contacts suggest contracts are being negotiated at around €450, effectively wiping out profits in the EU sugar industry.

While trading at the rest of the group is encouraging, Berenberg is cautious about assuming that Primark can maintain similar space and like-for-like sales growth in 2015 and 2016 to 2014. Hence Berenberg reduces its price target on ABF by around 7% and maintains a hold recommendation.

Whitbread fell 81p to £42.47 as UBS moved from neutral to sell and cut its price target from £44.50 to £42. The bank said the company's Premier Inn business could be hit by shared accommodation operations such as Airbnb.

But Barratt Developments built up a 10p rise to 389.3p after Wednesday's results when it reported doubled profits and predicted the UK housing market was returning to more normal trends.

A major faller was Aveva, off 548p or 25% to £16.20 after a shock profit warning. The software group said it would take a £14m hit from currency movements and the timing of contract renewals. Restructuring its sales organisation would also hit revenues, it said.

Finally online fashion retailer boohoo.com jumped 9% to 44.75p after it reported a 31% rise in half year revenue to around £67m.